20/09/2026
⛈️ AUSTRALIA'S STORM PATTERN CONTINUES TO GAIN INTEREST ⛈️
We've been monitoring the potential for an increasingly active period of thunderstorm weather across Australia through the second half of September, and after another look through the latest guidance this morning, the overall signal remains very much alive.
Before getting into it, I want to make one thing clear - this does NOT mean widespread severe thunderstorms are expected across Australia.
What we're seeing is a prolonged period where the ingredients for thunderstorms may come together across different parts of the country on different days. Exactly where the strongest storms develop will continue to change as we get closer.
Western Australia
WA is probably the most interesting area in the latest guidance.
Thunderstorms are already forecast across parts of the WA interior over the coming days, with heat, moisture and trough activity providing opportunities for afternoon and evening convection.
Further ahead, southern WA is something we're watching particularly closely.
Some of the longer range GFS guidance around Sunday the 27th is producing a very interesting severe weather environment in parts of southern WA.
One forecast sounding we analysed this morning showed roughly 1,200-1,700 J/kg of CAPE combined with more than 50 knots of deep layer wind shear, very little inhibition, reasonable low level moisture and elevated supercell/hail composite parameters.
Nearby, another forecast sounding had very little instability but an extremely strong and curved wind profile, including very large modelled storm-relative helicity.
This is where things become interesting - but also where we need to be careful.
At the moment, the best instability and most impressive wind profiles aren't perfectly overlapping. GFS has some very strong kinematics nearby, while EC is generally more enthusiastic with instability in some of the same broader areas but less aggressive with the wind profile.
Essentially, the ingredients are on the table, but the recipe hasn't come together yet.
If future runs begin bringing the stronger instability/moisture underneath the favourable wind profiles - while maintaining the steep lapse rates and sufficient forcing we've also been seeing - then the severe hunderstorm potential across parts of southern WA would become considerably more interesting.
For now, this remains something to watch rather than hype.
South Australia
SA remains involved in the broader pattern, particularly through inland and western areas as troughs and moisture interact with increasing daytime heating.
Thunderstorm opportunities may shift around considerably from day to day, and at this stage I don't see enough consistency to suggest a widespread severe setup.
There will, however, be the potential for individual stronger storms if sufficient instability develops alongside the stronger wind environment.
New South Wales & ACT
NSW continues to be another area we're monitoring through the coming week.
The overall pattern supports increasing moisture and periods of daytime instability interacting with troughs and local convergence zones. This could allow thunderstorms to develop across different parts of inland NSW before activity potentially shifts farther east at times.
At this stage, the signal is much stronger for multiple opportunities for convection than it is for a widespread organised severe-weather event.
Individual severe thunderstorms will certainly remain possible if stronger instability, steep lapse rates and locally favourable shear overlap, but we're not seeing enough consistency yet to start drawing severe risk areas.
Queensland
Queensland remains in the broader picture as moisture gradually becomes more important and the atmosphere begins transitioning further toward the warmer season pattern.
Inland and southern areas will be worth watching particularly closely as we move through the period.
Again, timing will be everything. Plenty of instability on a model doesn't automatically mean thunderstorms - we still need sufficient moisture, limited inhibition and a trigger to actually get parcels moving.
Victoria & Tasmania
These states currently have a weaker thunderstorm signal compared with some of the other areas we're watching.
Victoria in particular looks relatively quiet through the first part of the coming week in current official guidance, with the potential becoming less certain farther into the extended period.
That doesn't rule VIC or TAS out later. The synoptic pattern is still evolving, and small changes in the positioning and timing of the southern systems could change where instability and stronger upper winds overlap.
Northern Territory
Across the NT, isolated convection will also remain possible through parts of the period as heat and available moisture increase.
At this stage, however, our attention for the more organised thunderstorm potential remains farther south.
So what do we think?
The signal we're becoming increasingly confident in isn't one huge severe thunderstorm outbreak.
It's a prolonged and shifting period of thunderstorm opportunities across Australia, potentially affecting different regions on different days.
That distinction is important.
There will likely be days where storms struggle because moisture, instability, forcing or wind shear don't overlap properly. On other days, several of those ingredients may line up and allow stronger thunderstorms to develop.
Isolated severe thunderstorms during this period are absolutely possible.
What we currently do not have enough evidence for is a widespread severe outbreak.
Southern WA has particularly caught our attention because some of the extended guidance is producing some impressive severe weather parameters. But with around a week still to go, the exact placement of CAPE, moisture, shear and forcing can shift hundreds of kilometres between runs.
We'll be watching whether EC and GFS begin converging on the same solution rather than cherry picking whichever model shows the most extreme numbers.
That's the important part.
If the models eventually combine the instability currently shown in one solution with the much stronger wind environment shown in another, then we'll have something considerably more noteworthy to analyse.
For now: confidence is increasing in an active period of thunderstorms, confidence is much lower regarding exactly where severe thunderstorms occur, and there is currently no reason to hype this as a widespread severe weather outbreak.
I'll have a much more detailed storm analysis out as a reel as we get closer and can start properly narrowing down individual days, locations and potential hazards.
Plenty to watch over the next week. ⛈️
What part of Australia are you in? Drop your town below and I'll let you know how the current signal is looking for your area.
Cheers,
Kael - Dixons Weather Predictions
Independent weather analysis - not an official warning. Always follow current Bureau of Meteorology warnings and emergency-service advice.
